You can smile and stay firm, if they cry and beg you to continue picking up the check. 

I still wonder if they were fishing for some discrimination... some of their comments were a little ‘off color’ but I just smiled.

Then, you smile and make your exit.She will have to actually sue you, which most tenants won't do.  

Smile and leave.  

They're probably anxious as well, so if you show up with a couple of different win-win solutions, everyone will walk away smiling! 

And you can do that in a diplomatic way, while smiling (genuinely).  

Hey @Chris PohlsonHaving a script to fall back on certainly helps, but the biggest thing is to just take your lumps with a smile as you're building that skill set. 

I have professional tenants, so generally they don’t screw up the sliders :) but I smiled at the folks who said...closet doors are a problem?

If I could actually manage to evict her the my reward -- apart from putting a big smile on my neighbor's face -- would be losing at least 40K in rent (which I could not replace as the house will likely be sold at or near the end of the lease term).

And when they turn on the pressure and try to make you say yes right then and there, just keep smiling and repeating, "Well, I'm going to have to get back to you on that."